Adjustable attachment for loud-speaker units



Jan. 10, 1928..

H. A. SMITH ADJUSTABLE ATTACHMENT FOR LOUD SPEAKER UNITS I F iled Mame. 1926' I j 79 I50 8/ QINVENTOR arold' of. Smith i done lltt, lllll llltlh M 1: lt il ll il area or nun-Jedi; inertia" 3r.

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new i Application filed ."tttay 29, 19536. stun No. HEAWE.

armature link whereby the arn'iature may be pivotally adjusted between the polar extensions of the unit. Another object is to pro vide stop means for the adjusting screw that serves as a safety device for preventing undue strains to the armature and its connections.

l l/ith the above and other objects in view which will appear as the description proreeds, the invention consists oi? the novel construction, ada itation, combination and ar-' rangrement of parts hereinafter described and claimed. These objects are accoi'nplished by devices illustrated in the aceom ianying drawinggjs. wherein Figure 1 is a view in elevation of a loud speaker unit with certain parts broken away and showing my device attached thereto;

Fig. 2 is an enlarged sectional view taken substantially on a broken line 2. 2 t ll igl 1;

Fig. 3 is a top plan view cl' Fig. 1 with the cone portion removed; and

l is a sectional view taken on a broken line 4. 4 of Fig. 1.

Referring to the drawings throughout which like reference numerals designate like parts, the numeral 5 indicates a cone trame having a support 6 mounted thereupon which is provided with an extension 7. -k resilient bridge member 8 is secured to the upper side of said extension member and a llat sprin Si secured by adjusting; screws 10 engages said bridge member tor reasons presently set forth.

link extension 11 is lastened to the bridge 8 at a point 2 and a. lragrmeinary portion oi a cone '1 3 is shown mounted on the remote end of said link extension. The

o and alongside one of the til-shaped polar extensions 1? and is iastened at its other end portion lti toione end of the armature 19. riaid armature is centrally pivoted at between said polar extensions and windings 21 thereon as clearly shown in l ie'. 2 of the drawings. '1

The polar extensions 17 are secured to end portions of the permanent magnet 22 by screws 23 and one of saidextensions is rivcted at 52st to the cup 16 whose flange is secured to the cone frame 5 by screws at small tl-shapcd spring; 26 arranged. to yicldingly engage the tree end of the armature 19. The immediate foregoing "features are embodied in the device known as the Baldwin unit and form no part of the present invention except in so far as they may enter into novel -combination therewith. lit will be understood that my inventiim is not limited to a combination with the Baldwin unit and that same may be used in connection with any loud speaker unit to which it might be adapted.

i i casing 27 may be used to enclose the unit as a whole and an adjusting screw 28 provided with a knob 22) pass through the enclosure ot the magnet and through a slot 30 in the cup 16. Said screw is threadcdly mounted in the cone frame 5 witlritscnd portion projecting therethrough and engaging the outer end portion of the extension 7.

it will now be obvious that by turning the adjusting screw 28 in either direction the tension exerted by the spring 9 will cause the resilient bridge 8 to follow the screw. The armature link 1 1 bebop secured to said bridge at 15 will likewise be moved back and forth and its other end will move the armature 19 on its pivot point 20. that said armature may he pivotally adjusted between the polar extensions 17 and readily Thus it will be seen till ln'oiurht to a point midway thereliietweim to r ve the best vibratory results.

it. pin illiis secured through the end portion of the adj ustine" screw 28 and its ends are arranged to swingingly engage a projecting portion. 32 of one of the screws 25. This arrangement serves as a stop to limit the n'mvement of said adj ustinn :crew and conse quently the movement of the armature link l t and armature 19. i hen said pin reaches the limit of its swing and engages the screw 32 on either side said armature will impinge the edge portions ot the polar extensions i and can go no further. Undue or accidental strains will therefore be prevented from at fecting the 'armature and 1ts associated parts. Referring particularly to- Fig. 1, the

bridge arrangement shown therein is the most important part of my invention. The

point where the bridge 8 is supported by the adjusting screw 28, as designated by the numeral 33, serves as' a fulcrum, and the bridge from this point outwardly serves as a lever and is actuated by the vibratory function of the armature link 14 in moving the link extension 11' at the point 12. The resilient portion of said bridge extends, substantially from the point 12 to-the fulcrum v It is of primary importance that the portion of the bridge from the point 12 to the ,point 15, where said armature link is fas tened thereto, shall be stiff and inflexible. As shown in-the drawings, I have channeled this 'ortion of thebridge to give the re uire stifl'ness, although same may be made at and straight or in' any other form as long as thestiflness is' provided between these two points.

long as the point 12 where the leverage appears to be due to the fact that the lesser but, stronger vibrations correspond more closely'ih pitch with the nature of the cone or; d aphragm material. The increase in volume, which is more than double, may be tuned down if desired and will improve'the quality of the tone a corresponding amount. Having thus described my invention, it be ing understood that this disclosure is intended as an'illustrati'on vto'show one means of reducing my principle to practice and that such changes may be resortedto as are with-.

in the scope and spirit of my invention, what I claim and desire to secure by Letters Patent of the United States is 1. An, adjustable attachment for loud speaker units comprising a resilient bridge fixedly mounted at one of its ends, the other end connected to the armature link, a link extensionsecured to said bridgeintermediately'of said support and armature link connection, said armature piyotally disposed between its polar extens1ons,"adjusting means adapted to pivotally move the armature, and the portion of the bridge between said link extension and armature link of inflexible construction.

2. An adjustable attachment for loud speaker units comprising a resilient bridge mounted at one end on a. fixed support, the

other end connected to the armature link, a link extension secured to said bridge intermediately of said support and armature link connection, said armature piyotally dis- .posed between its polar extensions, adjusting means for said bridge adapted to pivotally move the armature through its link connection, the resilient portion of said bridge disposed between the point of contact of said ad usting means and the link extension, and the stiff portion of the bridge ex-- tending from said link extension to said armature link connect-ion.

v3. An adjustable attachment for loud speaker units comprising a resilient bridge mounted at oneend on a fixed support, the other end connected to the armature link, a link extension secured to said bridge intermediately of said support and armature link connection, an adjustable spring for said bridge, the armature pivotally disposed between its polar extensions, adjusting means for said bridge adapted to pivotally move the armature through its link connection, the resilient portion oi said bridge disposed between the point of contact of said adjusting means and the link extension, and the stiff portion of the bridge extending from said link extension to said armature link connection.

.4. An adjustable attachment Tlor loud speaker units comprising a resilient bridge mounted at one end on a fixed support, the

other end connected to the armature link, a

link extension secured to said bridge intermediately of said support and armature link connection, an adjustable spring for said bridge, the armature pivotally disposed betweenits polar extensions, an adjusting screw for said bridge adapted to pivotally move the armature by means of its linkcon- 'nection, stop means for said adjusting screw adapted to limit the pivotal movement of the armature, the resilient portion of said bridge disposed between thepoint of engagement of said screw and the link extension, and the portion of the bridge between said link extension and armature link being ii In witness whereof, I hereunto subscribe my name this'20th day of May, A. D. 1926. HAROLD A. SMITH. 

